Pulsed NMR spectroscopy is described in our above-cited U.S. application Ser. No. 374,493. This technique uses a burst or pulse which is designed to excite all the nuclei of a particular nuclear species of a sample being measured (the protons, or the like, of such sample having first been precessed in an essentially static magnetic field); in other words the precession is modified by the pulse. After the application of the pulse there occurs a free induction decay (FID) of the magnetization associated with the excited nuclei. Traditional Fourier Transform analysis generates a frequency domain spectrum which can be used to advantage in studying the nuclei of interest. The duration of the pulses, the time between the pulses, the pulse phase angle and the composition of the sample are parameters which affect the sensitivity of this technique. These frequency domain techniques are not easily useable in industrial applications, especially on-line applications.
Application Ser. No. 374,493 showed an improved NMR measurement system which leads to accurate, fast determination of the types and quantity of the nuclear species of interest, the use of time domain analysis in such a system, its application to the industrial, on-line problems of monitoring and controlling processes, measuring free and bound water in organic or inorganic substances (based on hydrogen nuclei modified-precession analysis) and other parameter measurement (based on hydrogen or other sensitive species including e.g., sodium-23or carbon-13), accommodating the dynamics of industrial on-line applications including variations of density, temperature, packing and size factors, friction and static electricity, vibration and frequent, repetitive, cyclic and non-cyclic measurements, and using such magnetic resonance techniques in polymer analysis, including density, all with enhanced accuracy and reliability of data obtained and while achieving the necessary practical economies.
The object of the present invention is to extend those achievements further in relation to industrial on-line processing, and the like, as applied to mixed species (or mixed phases) of NMR-active materials and more particularly foodstuffs and plastics materials (and being applicable to many other NMR-active materials) with a third component such as oils/fats or solvents in addition to two main components (moisture/solids, crystalline/amorphous).